Mercer County, NJ Property Tax: $8,804/yr (2026)
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The effective property tax rate in Mercer County is 2.51% of assessed home value. On a home at the county median value of $351,000, that works out to about $8,810 per year, or $734 per month. Mercer County is located in central New Jersey, and is home to approximately 383,286 residents.
About Mercer County
Mercer County covers approximately 224.5 square miles in New Jersey. The county is home to about 383,286 residents living in roughly 150,600 housing units, of which 58.1% are owner-occupied. The median household income is $96,333, and the median home was built in 1967.
Mercer County borders Burlington County, Hunterdon County, Middlesex County, Monmouth County, Somerset County — useful comparisons if you're considering nearby areas with potentially different tax rates.
How Property Taxes Work in New Jersey
Property taxes in New Jersey are administered at the county level. Each county sets a millage rate applied to the assessed value of real property — the effective rate above accounts for any partial assessments and exemptions already built into the local tax base. Assessed value can differ meaningfully from current market value depending on how often the county reassesses and what fraction of market value it uses.
Most counties in New Jersey offer exemptions that reduce the taxable assessed value: homestead exemptions for primary residences, senior exemptions, disability exemptions, and veteran exemptions are common. These reduce your effective rate below the county-wide average shown here. Contact the Mercer County Assessor's office to learn which exemptions apply to your property and when to file.
Mercer County vs. Neighboring Counties
| Location | Eff. Rate | Median Home | Annual Tax |
|---|---|---|---|
| Mercer County, NJ | 2.51% | $351,000 | $8,810 |
| New Jersey state average | 2.21% | — | $7,757* |
| Burlington County | 2.42% | $326,700 | $7,902 |
| Hunterdon County | 2.01% | $498,800 | $10,001 |
| Middlesex County | 2.20% | $439,300 | $9,684 |
| Monmouth County | 1.77% | $566,500 | $10,001 |
| Somerset County | 1.91% | $523,900 | $10,001 |
| US national average | 1.10% | $281,900 | $3,101 |
*State average annual tax computed at Mercer County's median home value of $351,000. Source: US Census ACS 2023 5-year estimates.
Frequently Asked Questions
How does Mercer County's property tax rate compare to the rest of New Jersey?
At 2.51%, Mercer County is higher than the New Jersey state average of 2.21%. On a home at the county median of $351,000, that means about $8,810 per year — versus $7,757 at the state average rate, a difference of $1,053 per year. Compared to the national average of 1.10%, Mercer County is above average.
What's a typical annual property tax bill in Mercer County?
For a home at the county median value of $351,000, the annual property tax in Mercer County is approximately $8,810 — or about $734 per month. For a home worth $526,500, expect around $13,215 per year. For a $702,000 home, approximately $17,620 per year. Use the calculator above to estimate taxes for any assessed value.
Where do I appeal a Mercer County property tax assessment?
Property assessment appeals in Mercer County are handled by the Mercer County Assessor's office. Most jurisdictions require filing within 30–90 days of receiving your assessment notice — confirm the specific deadline with the assessor's office before submitting, as deadlines and procedures vary by county. A successful appeal can reduce your assessed value and lower your tax bill for the current and future tax years.
What exemptions are available in Mercer County?
New Jersey counties commonly offer homestead exemptions for owner-occupied primary residences, senior citizen exemptions for qualifying homeowners aged 65 and older, exemptions for disabled residents, and veterans' exemptions. Each exemption reduces your assessed taxable value, which in turn reduces your effective tax rate below the county-wide 2.51% shown here. Contact the Mercer County Assessor's office to confirm which exemptions are available and the application deadlines.
Data sources: US Census Bureau ACS 2023 5-Year Estimates, US Census Gazetteer (2024), County Adjacency File